框架----Django之Form组件

Django的Form主要具有一下几大功能:

  • 生成HTML标签
  • 验证用户数据(显示错误信息)
  • HTML Form提交保留上次提交数据
  • 初始化页面显示内容

一、小试牛刀

1、创建Form类

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4  
 5 class MyForm(Form):
 6     user = fields.CharField(
 7         widget=widgets.TextInput(attrs={'id': 'i1', 'class': 'c1'})
 8     )
 9  
10     gender = fields.ChoiceField(
11         choices=((1, ''), (2, ''),),
12         initial=2,
13         widget=widgets.RadioSelect
14     )
15  
16     city = fields.CharField(
17         initial=2,
18         widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
19     )
20  
21     pwd = fields.CharField(
22         widget=widgets.PasswordInput(attrs={'class': 'c1'}, render_value=True)
23     )
View Code

2、View函数处理

 1 from django.shortcuts import render, redirect
 2 from .forms import MyForm
 3  
 4  
 5 def index(request):
 6     if request.method == "GET":
 7         obj = MyForm()
 8         return render(request, 'index.html', {'form': obj})
 9     elif request.method == "POST":
10         obj = MyForm(request.POST, request.FILES)
11         if obj.is_valid():
12             values = obj.clean()
13             print(values)
14         else:
15             errors = obj.errors
16             print(errors)
17         return render(request, 'index.html', {'form': obj})
18     else:
19         return redirect('http://www.google.com')
View Code

3、生成HTML

1 
"/" method="POST" enctype="multipart/form-data"> 2

{{ form.user }} {{ form.user.errors }}

3

{{ form.gender }} {{ form.gender.errors }}

4

{{ form.city }} {{ form.city.errors }}

5

{{ form.pwd }} {{ form.pwd.errors }}

6 "submit"/> 7
View Code
 1 
"POST" enctype="multipart/form-data"> 2 {% csrf_token %} 3 4 {{ form.xxoo.label }} 5 {{ form.xxoo.id_for_label }} 6 {{ form.xxoo.label_tag }} 7 {{ form.xxoo.errors }} 8

{{ form.user }} {{ form.user.errors }}

9 "submit" /> 10
11 12 其他标签有
其他标签有

二、Form类

创建Form类时,主要涉及到 【字段】 和 【插件】,字段用于对用户请求数据的验证,插件用于自动生成HTML;

1、Django内置字段如下:

  1 Field
  2     required=True,               是否允许为空
  3     widget=None,                 HTML插件
  4     label=None,                  用于生成Label标签或显示内容
  5     initial=None,                初始值
  6     help_text='',                帮助信息(在标签旁边显示)
  7     error_messages=None,         错误信息 {'required': '不能为空', 'invalid': '格式错误'}
  8     show_hidden_initial=False,   是否在当前插件后面再加一个隐藏的且具有默认值的插件(可用于检验两次输入是否一直)
  9     validators=[],               自定义验证规则
 10     localize=False,              是否支持本地化
 11     disabled=False,              是否可以编辑
 12     label_suffix=None            Label内容后缀
 13  
 14  
 15 CharField(Field)
 16     max_length=None,             最大长度
 17     min_length=None,             最小长度
 18     strip=True                   是否移除用户输入空白
 19  
 20 IntegerField(Field)
 21     max_value=None,              最大值
 22     min_value=None,              最小值
 23  
 24 FloatField(IntegerField)
 25     ...
 26  
 27 DecimalField(IntegerField)
 28     max_value=None,              最大值
 29     min_value=None,              最小值
 30     max_digits=None,             总长度
 31     decimal_places=None,         小数位长度
 32  
 33 BaseTemporalField(Field)
 34     input_formats=None          时间格式化   
 35  
 36 DateField(BaseTemporalField)    格式:2015-09-01
 37 TimeField(BaseTemporalField)    格式:11:12
 38 DateTimeField(BaseTemporalField)格式:2015-09-01 11:12
 39  
 40 DurationField(Field)            时间间隔:%d %H:%M:%S.%f
 41     ...
 42  
 43 RegexField(CharField)
 44     regex,                      自定制正则表达式
 45     max_length=None,            最大长度
 46     min_length=None,            最小长度
 47     error_message=None,         忽略,错误信息使用 error_messages={'invalid': '...'}
 48  
 49 EmailField(CharField)      
 50     ...
 51  
 52 FileField(Field)
 53     allow_empty_file=False     是否允许空文件
 54  
 55 ImageField(FileField)      
 56     ...
 57     注:需要PIL模块,pip3 install Pillow
 58     以上两个字典使用时,需要注意两点:
 59         - form表单中 enctype="multipart/form-data"
 60         - view函数中 obj = MyForm(request.POST, request.FILES)
 61  
 62 URLField(Field)
 63     ...
 64  
 65  
 66 BooleanField(Field)  
 67     ...
 68  
 69 NullBooleanField(BooleanField)
 70     ...
 71  
 72 ChoiceField(Field)
 73     ...
 74     choices=(),                选项,如:choices = ((0,'上海'),(1,'北京'),)
 75     required=True,             是否必填
 76     widget=None,               插件,默认select插件
 77     label=None,                Label内容
 78     initial=None,              初始值
 79     help_text='',              帮助提示
 80  
 81  
 82 ModelChoiceField(ChoiceField)
 83     ...                        django.forms.models.ModelChoiceField
 84     queryset,                  # 查询数据库中的数据
 85     empty_label="---------",   # 默认空显示内容
 86     to_field_name=None,        # HTML中value的值对应的字段
 87     limit_choices_to=None      # ModelForm中对queryset二次筛选
 88      
 89 ModelMultipleChoiceField(ModelChoiceField)
 90     ...                        django.forms.models.ModelMultipleChoiceField
 91  
 92  
 93      
 94 TypedChoiceField(ChoiceField)
 95     coerce = lambda val: val   对选中的值进行一次转换
 96     empty_value= ''            空值的默认值
 97  
 98 MultipleChoiceField(ChoiceField)
 99     ...
100  
101 TypedMultipleChoiceField(MultipleChoiceField)
102     coerce = lambda val: val   对选中的每一个值进行一次转换
103     empty_value= ''            空值的默认值
104  
105 ComboField(Field)
106     fields=()                  使用多个验证,如下:即验证最大长度20,又验证邮箱格式
107                                fields.ComboField(fields=[fields.CharField(max_length=20), fields.EmailField(),])
108  
109 MultiValueField(Field)
110     PS: 抽象类,子类中可以实现聚合多个字典去匹配一个值,要配合MultiWidget使用
111  
112 SplitDateTimeField(MultiValueField)
113     input_date_formats=None,   格式列表:['%Y--%m--%d', '%m%d/%Y', '%m/%d/%y']
114     input_time_formats=None    格式列表:['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
115  
116 FilePathField(ChoiceField)     文件选项,目录下文件显示在页面中
117     path,                      文件夹路径
118     match=None,                正则匹配
119     recursive=False,           递归下面的文件夹
120     allow_files=True,          允许文件
121     allow_folders=False,       允许文件夹
122     required=True,
123     widget=None,
124     label=None,
125     initial=None,
126     help_text=''
127  
128 GenericIPAddressField
129     protocol='both',           both,ipv4,ipv6支持的IP格式
130     unpack_ipv4=False          解析ipv4地址,如果是::ffff:192.0.2.1时候,可解析为192.0.2.1, PS:protocol必须为both才能启用
131  
132 SlugField(CharField)           数字,字母,下划线,减号(连字符)
133     ...
134  
135 UUIDField(CharField)           uuid类型
136     ...
View Code

注:UUID是根据MAC以及当前时间等创建的不重复的随机字符串

 1 >>> import uuid
 2 
 3     # make a UUID based on the host ID and current time
 4     >>> uuid.uuid1()    # doctest: +SKIP
 5     UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
 6 
 7     # make a UUID using an MD5 hash of a namespace UUID and a name
 8     >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
 9     UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
10 
11     # make a random UUID
12     >>> uuid.uuid4()    # doctest: +SKIP
13     UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
14 
15     # make a UUID using a SHA-1 hash of a namespace UUID and a name
16     >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
17     UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
18 
19     # make a UUID from a string of hex digits (braces and hyphens ignored)
20     >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')
21 
22     # convert a UUID to a string of hex digits in standard form
23     >>> str(x)
24     '00010203-0405-0607-0809-0a0b0c0d0e0f'
25 
26     # get the raw 16 bytes of the UUID
27     >>> x.bytes
28     b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'
29 
30     # make a UUID from a 16-byte string
31     >>> uuid.UUID(bytes=x.bytes)
32     UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
View Code

2、Django内置插件:

TextInput(Input)
NumberInput(TextInput)
EmailInput(TextInput)
URLInput(TextInput)
PasswordInput(TextInput)
HiddenInput(TextInput)
Textarea(Widget)
DateInput(DateTimeBaseInput)
DateTimeInput(DateTimeBaseInput)
TimeInput(DateTimeBaseInput)
CheckboxInput
Select
NullBooleanSelect
SelectMultiple
RadioSelect
CheckboxSelectMultiple
FileInput
ClearableFileInput
MultipleHiddenInput
SplitDateTimeWidget
SplitHiddenDateTimeWidget
SelectDateWidget
View Code

三、常用选择插件

 1 # 单radio,值为字符串
 2 # user = fields.CharField(
 3 #     initial=2,
 4 #     widget=widgets.RadioSelect(choices=((1,'上海'),(2,'北京'),))
 5 # )
 6  
 7 # 单radio,值为字符串
 8 # user = fields.ChoiceField(
 9 #     choices=((1, '上海'), (2, '北京'),),
10 #     initial=2,
11 #     widget=widgets.RadioSelect
12 # )
13  
14 # 单select,值为字符串
15 # user = fields.CharField(
16 #     initial=2,
17 #     widget=widgets.Select(choices=((1,'上海'),(2,'北京'),))
18 # )
19  
20 # 单select,值为字符串
21 # user = fields.ChoiceField(
22 #     choices=((1, '上海'), (2, '北京'),),
23 #     initial=2,
24 #     widget=widgets.Select
25 # )
26  
27 # 多选select,值为列表
28 # user = fields.MultipleChoiceField(
29 #     choices=((1,'上海'),(2,'北京'),),
30 #     initial=[1,],
31 #     widget=widgets.SelectMultiple
32 # )
33  
34  
35 # 单checkbox
36 # user = fields.CharField(
37 #     widget=widgets.CheckboxInput()
38 # )
39  
40  
41 # 多选checkbox,值为列表
42 # user = fields.MultipleChoiceField(
43 #     initial=[2, ],
44 #     choices=((1, '上海'), (2, '北京'),),
45 #     widget=widgets.CheckboxSelectMultiple
46 # )
View Code

在使用选择标签时,需要注意choices的选项可以从数据库中获取,但是由于是静态字段 ***获取的值无法实时更新***,那么需要自定义构造方法从而达到此目的。

方式一:

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4 from django.core.validators import RegexValidator
 5  
 6 class MyForm(Form):
 7  
 8     user = fields.ChoiceField(
 9         # choices=((1, '上海'), (2, '北京'),),
10         initial=2,
11         widget=widgets.Select
12     )
13  
14     def __init__(self, *args, **kwargs):
15         super(MyForm,self).__init__(*args, **kwargs)
16         # self.fields['user'].widget.choices = ((1, '上海'), (2, '北京'),)
17         #
18         self.fields['user'].widget.choices = models.Classes.objects.all().value_list('id','caption')
View Code

方式二:

使用django提供的ModelChoiceField和ModelMultipleChoiceField字段来实现

 1 from django import forms
 2 from django.forms import fields
 3 from django.forms import widgets
 4 from django.forms import models as form_model
 5 from django.core.exceptions import ValidationError
 6 from django.core.validators import RegexValidator
 7  
 8 class FInfo(forms.Form):
 9     authors = form_model.ModelMultipleChoiceField(queryset=models.NNewType.objects.all())
10     # authors = form_model.ModelChoiceField(queryset=models.NNewType.objects.all())
View Code

四、自定义验证规则

方式一:

1 from django.forms import Form
2 from django.forms import widgets
3 from django.forms import fields
4 from django.core.validators import RegexValidator
5  
6 class MyForm(Form):
7     user = fields.CharField(
8         validators=[RegexValidator(r'^[0-9]+$', '请输入数字'), RegexValidator(r'^159[0-9]+$', '数字必须以159开头')],
9     )
View Code

方式二:

 1 import re
 2 from django.forms import Form
 3 from django.forms import widgets
 4 from django.forms import fields
 5 from django.core.exceptions import ValidationError
 6  
 7  
 8 # 自定义验证规则
 9 def mobile_validate(value):
10     mobile_re = re.compile(r'^(13[0-9]|15[012356789]|17[678]|18[0-9]|14[57])[0-9]{8}$')
11     if not mobile_re.match(value):
12         raise ValidationError('手机号码格式错误')
13  
14  
15 class PublishForm(Form):
16  
17  
18     title = fields.CharField(max_length=20,
19                             min_length=5,
20                             error_messages={'required': '标题不能为空',
21                                             'min_length': '标题最少为5个字符',
22                                             'max_length': '标题最多为20个字符'},
23                             widget=widgets.TextInput(attrs={'class': "form-control",
24                                                           'placeholder': '标题5-20个字符'}))
25  
26  
27     # 使用自定义验证规则
28     phone = fields.CharField(validators=[mobile_validate, ],
29                             error_messages={'required': '手机不能为空'},
30                             widget=widgets.TextInput(attrs={'class': "form-control",
31                                                           'placeholder': u'手机号码'}))
32  
33     email = fields.EmailField(required=False,
34                             error_messages={'required': u'邮箱不能为空','invalid': u'邮箱格式错误'},
35                             widget=widgets.TextInput(attrs={'class': "form-control", 'placeholder': u'邮箱'}))
View Code

方法三:自定义方法

 1 from django import forms
 2     from django.forms import fields
 3     from django.forms import widgets
 4     from django.core.exceptions import ValidationError
 5     from django.core.validators import RegexValidator
 6  
 7     class FInfo(forms.Form):
 8         username = fields.CharField(max_length=5,
 9                                     validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.', 'invalid')], )
10         email = fields.EmailField()
11  
12         def clean_username(self):
13             """
14             Form中字段中定义的格式匹配完之后,执行此方法进行验证
15             :return:
16             """
17             value = self.cleaned_data['username']
18             if "666" in value:
19                 raise ValidationError('666已经被玩烂了...', 'invalid')
20             return value
View Code

方式四:同时生成多个标签进行验证

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4  
 5 from django.core.validators import RegexValidator
 6  
 7  
 8 ############## 自定义字段 ##############
 9 class PhoneField(fields.MultiValueField):
10     def __init__(self, *args, **kwargs):
11         # Define one message for all fields.
12         error_messages = {
13             'incomplete': 'Enter a country calling code and a phone number.',
14         }
15         # Or define a different message for each field.
16         f = (
17             fields.CharField(
18                 error_messages={'incomplete': 'Enter a country calling code.'},
19                 validators=[
20                     RegexValidator(r'^[0-9]+$', 'Enter a valid country calling code.'),
21                 ],
22             ),
23             fields.CharField(
24                 error_messages={'incomplete': 'Enter a phone number.'},
25                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid phone number.')],
26             ),
27             fields.CharField(
28                 validators=[RegexValidator(r'^[0-9]+$', 'Enter a valid extension.')],
29                 required=False,
30             ),
31         )
32         super(PhoneField, self).__init__(error_messages=error_messages, fields=f, require_all_fields=False, *args,
33                                          **kwargs)
34  
35     def compress(self, data_list):
36         """
37         当用户验证都通过后,该值返回给用户
38         :param data_list:
39         :return:
40         """
41         return data_list
42  
43 ############## 自定义插件 ##############
44 class SplitPhoneWidget(widgets.MultiWidget):
45     def __init__(self):
46         ws = (
47             widgets.TextInput(),
48             widgets.TextInput(),
49             widgets.TextInput(),
50         )
51         super(SplitPhoneWidget, self).__init__(ws)
52  
53     def decompress(self, value):
54         """
55         处理初始值,当初始值initial不是列表时,调用该方法
56         :param value:
57         :return:
58         """
59         if value:
60             return value.split(',')
61         return [None, None, None]
View Code

五、初始化数据

在Web应用程序中开发编写功能时,时常用到获取数据库中的数据并将值初始化在HTML中的标签上。

1、Form

 1 from django.forms import Form
 2 from django.forms import widgets
 3 from django.forms import fields
 4 from django.core.validators import RegexValidator
 5  
 6  
 7 class MyForm(Form):
 8     user = fields.CharField()
 9  
10     city = fields.ChoiceField(
11         choices=((1, '上海'), (2, '北京'),),
12         widget=widgets.Select
13     )
View Code

2、Views

 1 from django.shortcuts import render, redirect
 2 from .forms import MyForm
 3  
 4  
 5 def index(request):
 6     if request.method == "GET":
 7         values = {'user': 'root', 'city': 2}
 8         obj = MyForm(values)
 9  
10         return render(request, 'index.html', {'form': obj})
11     elif request.method == "POST":
12         return redirect('http://www.google.com')
13     else:
14         return redirect('http://www.google.com')
View Code

3、HTML

1 
"POST" enctype="multipart/form-data"> 2 {% csrf_token %} 3

{{ form.user }} {{ form.user.errors }}

4

{{ form.city }} {{ form.city.errors }}

5 6 "submit"/> 7
View Code

 

转载于:https://www.cnblogs.com/wangyongsong/p/7111115.html

你可能感兴趣的:(数据库,python)